1. Field of the Invention
The present invention relates to a disk brake assembly for wheeled vehicles, and more particularly to a disk brake assembly including an outer pad which is rigidly supported on a caliper member and which does not rattle or vibrate.
2. Description of the Prior Art
A conventional disk brake assembly is disclosed, for example, in Japanese application laid-open publication No. 58-118326 published on Aug. 12, 1983. This conventional disk brake assembly includes an outer pad having an outwardly projecting portion at its backing plate and a plate spring member for rigidly supporting the outer pad on a caliper member. The plate spring member is formed by press forming and includes a central annular portion having an engaging hole or opening and a pair of first spring arm portions extending from the central annular portion toward to the circumference of the brake disk and a second spring arm portion extending outwardly from the central annular portion to the radial direction of the brake disk. The engaging hole or opening of the central annular portion is provided with two engaging nail portions which are rigidly engaged with a projection portion of a backing plate of the outer pad, and the first spring arm portion engages with the two nail portions of the reaction portion of the caliper member at its end portions and urges the outer pad toward to the outer side of the brake disk. The second spring arm portion engages with the reaction portion of the caliper member at its end portion and urges the outer pad toward to the center of the brake disk.
In the above conventional disk brake assembly, however, since the outer pad is rigidly supported on the caliper member by means of the rigid snapping engagement of the engaging nail portions of the central annular portion of the plate spring member, it is necessary to strictly control the tolerances of the plate spring member during manufacture. Therefore, there is a drawback that manufacturing cost of the plate spring member is increased due to the above strict control of the tolerences during its manufacture and of the press forming process. Reuse of the plate spring member, after its installation and its removal is prevented by the transformation of the engaging nail portions of the central annular portion and wear of the projection portion of the outer pad. Therefore, proper performance of the plate spring member, for a period of extended use is less than desirable.